In the construction industry, structures can be coated with passive fireproofing material. Fireproofing material is known to provide fire resistance to steel elements of buildings. Fireproofing material is used to produce coatings over a substrate to be protected. The coatings can be held together by organic or inorganic binders. Those with inorganic binders are the primary subject of this disclosure and will be referred to as “inorganic fireproofing”, “spray-applied fireproofing material” or “SFRM”. Other fireproofing wherein the primary binders are organic chemicals are often referred to as “intumescing fire-resistive materials” or “IFRM”.
SFRMs usually consist of inorganic binders such as plaster or Portland cement, and various fillers such as vermiculite, mica, calcium silicate, gypsum, lightweight polystyrene beads, mineral wool, glass fibers, ceramic fibers, aluminum ore, clay and quartz. Examples of plaster-based fireproofing products are Cafco® 300 from Isolatek International, Pyrolite® 15 from Carboline and Monokote® MK-6 from W. R. Grace. Examples of Portland-cement-based fireproofing products are Fendolite® MII from Isolatek International, Pyrocrete® 241 from Carboline and Monokote® Type Z-146 from W. R. Grace.
Passive fireproofing materials, once applied, are often coated. The coatings can provide additional durability, particularly against negative effects caused by corrosive chemicals or the ingress of water from rain, washing and salt water. Physical degradation from freeze-thaw cycles is an example of such a negative effect. It is common in the industry to use a non-aqueous (i.e., organic based) sealant as the coating. These organic based coatings can act as a sealant and/or a top-primer for subsequent application of other protective or decorative coatings, such as paint. An example of an organic based sealant is Carboguard® 1340.
It is beneficial to apply the coating soon after the fireproofing material has been applied to a substrate. Application of the coating within a few hours or a few days can reduce the cost of scaffolding or other construction support. Once the fireproofing material has been coated, these construction supports can be removed. The ability for construction to progress without the delay of waiting for the coating to be applied can reduce rental costs and free the area for other uses. Prompt coating can also reduce the rate of early drying. It can also allow for good curing and strength development, particularly in hot and/or dry conditions.
In most applications, it is beneficial for the coating to uniformly coat the fireproofing material. Applied fireproofing can be thick (e.g., 1-2 inches or more) and can initially contain substantial water (e.g., 30-70%). Depending on environmental conditions, applied fireproofing can require a number of days for curing. Coatings, such as Carboguard® 1340, do not provide a sufficiently uniform coating when applied soon after the fireproofing material has been applied. Due to the high water content, the non-aqueous and hydrophilic liquid tends to pool or bead up when applied which results in a spotty, non-uniform coating. Accordingly, this non-uniform coating can then fail to provide the desired enhancement of durability and/or reduction of early drying rates.
The present disclosure relates to coating compositions, kits, and methods of applying the same, for use with fireproofing materials. The coating compositions are effective to control the drying rate and shrinkage of fireproofing materials. They are also able to be applied to fireproofing materials shortly after these materials have been applied to a substrate.